import math
s = input().split(" ")
n = list(map(float,s))
d = math.sqrt((n[0]-n[2])**2 + (n[1]-n[3])**2)
print(d) import math math s = input().split(" ") s input().split(" ") ().split () input split " " n = list(map(float,s)) n list(map(float,s)) list map(float,s) map float s d = math.sqrt((n[0]-n[2])**2 + (n[1]-n[3])**2) d math.sqrt((n[0]-n[2])**2 + (n[1]-n[3])**2) math.sqrt math sqrt (n[0]-n[2])**2 + (n[1]-n[3])**2 (n[0]-n[2])**2 n[0]-n[2] n[0] n 0 n[2] n 2 2 (n[1]-n[3])**2 n[1]-n[3] n[1] n 1 n[3] n 3 2 print(d) print d s = input().split(" ") input().split(" ") s d = math.sqrt((n[0]-n[2])**2 + (n[1]-n[3])**2) math.sqrt((n[0]-n[2])**2 + (n[1]-n[3])**2) d n = list(map(float,s)) list(map(float,s)) n
import math
s = input().split(" ")
n = list(map(float,s))
d = math.sqrt((n[0]-n[2])**2 + (n[1]-n[3])**2)
print(d)